Christian A. Gonzalez

Multimodal urgency coding: auditory, visual, and tactile parameters and their impact on perceived urgency

Through a series of investigations involving different levels of contextual fidelity we developed scales of perceived urgency for several dimensions of the auditory, visual, and tactile modalities. Psychophysical ratings of perceived urgency, annoyance, and acceptability as well as behavioral responses to signals in each modality were obtained and analyzed using Stevens Power Law to allow comparison across modalities. Obtained results and their implications for use as in-vehicle alerts and warnings are discussed.

Perceived Urgency Scaling in Tactile Alerts

Tactile vibrations are potentially useful in a variety of environments to communicate information to visually and auditorily overloaded people. However, since vibrotactile signals must come into physical contact with the skin, they may also be perceived as highly urgent and annoying. The current study examined whether scalable levels of perceived urgency could be obtained with tactile signals by measuring the relationship between changes in vibrotactile pulse rate and ratings of urgency and annoyance. In two separate experiments, changes in pulse rate resulted in changes in ratings of perceived urgency with faster pulse rates being perceived as more urgent. Importantly, in both studies pulse rate had a greater impact on perceived urgency than it did on annoyance suggesting that scalable levels of urgency can be achieved without similarly annoying operators. Results are discussed in terms of their implications for multimodal display design.

Seeing Minds in Others - Can Agents with Robotic Appearance Have Human-Like Preferences?

Ascribing mental states to non-human agents has been shown to increase their likeability and lead to better joint-task performance in human-robot interaction (HRI). However, it is currently unclear what physical features non-human agents need to possess in order to trigger mind attribution and whether different aspects of having a mind (e.g., feeling pain, being able to move) need different levels of human-likeness before they are readily ascribed to non-human agents. The current study addresses this issue by modeling how increasing the degree of human-like appearance (on a spectrum from mechanistic to humanoid to human) changes the likelihood by which mind is attributed towards non-human agents. We also test whether different internal states (e.g., being hungry, being alive) need different degrees of humanness before they are ascribed to non-human agents. The results suggest that the relationship between physical appearance and the degree to which mind is attributed to non-human agents is best described as a two-linear model with no change in mind attribution on the spectrum from mechanistic to humanoid robot, but a significant increase in mind attribution as soon as human features are included in the image. There seems to be a qualitative difference in the perception of mindful versus mindless agents given that increasing human-like appearance alone does not increase mind attribution until a certain threshold is reached, that is: agents need to be classified as having a mind first before the addition of more human-like features significantly increases the degree to which mind is attributed to that agent.

Perceived Urgency and Annoyance of Auditory Alerts in a Driving Context

Complex in-vehicle technology and safety systems are finding their way into many cars on the road today. These systems require alerts and warnings that appropriately convey multiple levels of urgency, but if these are deemed excessively annoying, then their implementation may be of little consequence. In this study we used a well-documented psychophysical approach to identify the relationship between specific auditory parameters, perceived urgency and perceived annoyance. In agreement with existing literature, increases in all parameters led to increases in both urgency and annoyance - although differentially. Of the parameters investigated, only pulse rate exhibited a stronger psychophysical relationship with urgency than annoyance. The tradeoff between urgency and annoyance is of practical concern and results from this study provide a potential guideline to determine the viability of future in vehicle alerts based on this relationship.

A New Behavioral Measure of Cognitive Flexibility

Individual differences in cognitive flexibility may underlie a variety of different user behaviors, but a lack of effective measurement tools has limited the predictive and descriptive potential of cognitive flexibility in human-computer interaction applications. This study presents a new computerized measure of cognitive flexibility, and then provides evidence for convergent validity. Our findings indicate moderate to strong correlations with the Trail Making Task, and in particular, those aspects of the task most closely associated with cognitive flexibility. Results of this study provide support for the validity of a new measure of cognitive flexibility. We conclude by discussing the measures potential applicability in the field of HCI.

Perspectives on the Training of Human Factors Students for the User Experience Industry

We surveyed 140 HFES student members and found that nearly 80% of students were considering a future career in UX. In contrast, only 12% felt that their training has prepared them extremely well for a UX career. An analysis of 40 UX job postings revealed that while these positions required some human factors related skills, 37% of their job requirements emphasized design familiarity and programming skills. Students indicated that gaps in their education and preparation represent the largest challenge they face in entering the UX field. They further identified the broad definition of UX and lack of access to industry positions as other challenges in transitioning to UX professionals. It is recommended to focus on increasing HFES’s relevance to students interested in future UX careers.

The Effects of Task-Set Switching On Concurrent Verbal Protocol

Concurrent verbal protocol (CVP) is a common usability testing and analysis technique that requires people to continuously vocalize their thoughts as they complete a task. Given the widespread use of concurrent verbal protocols in applied domains, it is surprising how little is known regarding concurrent verbal protocol’s effect on task performance. In the current series of studies, we examined how concurrent verbal protocols affected performance on two tasks that required users to frequently switch between cognitive strategies. Data revealed that CVP slowed down participants in comparison with participants who completed tasks in silence. The number of strategy changes that were required to complete a task did not affect this performance decrement. We conclude by discussing the limitations of the experiments reported here, and with practical advice for usability experts who use CVP in their own work.

Creating a Computerized Assessment of Cognitive Flexibility with a User-Friendly Participant and Experimenter Interface

Researchers are often faced with practical hurdles to data collection stemming from poorly designed research tools. In this set of studies, we utilized an iterative design process to develop a new assessment of individual differences in cognitive flexibility. The development cycle began with paper prototypes of the cognitive flexibility assessment and ended with a computerized prototype research tool. Here we outline our development process, report results from user testing, and demonstrate how human factors methodology, often used in product design, can also be successfully utilized to test and improve the user friendliness of psychology assessment tools.

Correction: Seeing Minds in Others – Can Agents with Robotic Appearance Have Human-Like Preferences?

The following information is missing from the Funding section: Publication of this article was funded in part by the George Mason University Libraries Open Access Publishing Fund.

Effects of pulse rate, fundamental frequency and burst density on auditory similarity

Auditory displays are currently used in many medical, automotive and aviation settings. Although there are many existing guidelines for developing effective auditory signals, there is a need for more research considering the interaction between signals within a display, especially when sounds originate from conceptually distinct referent systems. Identifying the parameters that are most relevant to auditory similarity can facilitate acoustic branding and the development of guidelines that ensure signals for different systems are distinct without requiring standardisation. Twenty-seven undergraduate students judged the similarity of a set of abstract sounds varying in tempo, or pulse rate, fundamental frequency and burst density. Results indicate that no single parameter is entirely responsible for determining auditory similarity, but temporal characteristics are most salient. These findings have implications for acoustic branding and suggest that designers intending to ensure perceptual similarity and separation between differentially mapped sounds should manipulate temporal characteristics before frequency or burst density.